cxl/features: Remove the inline specifier from to_cxlfs()

cxl/features: Remove the inline specifier from to_cxlfs()

to_cxlfs() was declared 'inline' in the header but only defined in
drivers/cxl/core/features.c. This has worked because features.c was
the only file using the function and the definition happened to be
available in the same compilation unit.

However, in preparation for a second .c file using the header and
needing to call the function, the inline specifier became an issue.
Sparse flagged the declaration as invalid since 'inline' requires a
visible definition at the point of use.

Defining the function in the header was considered but rejected, as
it depends on internal symbols not visible at that level.

Remove the inline specifier to correct the linkage violation.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Shiju Jose <shiju.jose@huawei.com>
Link: https://patch.msgid.link/20250521233625.1745849-1-alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>